Ivo Raisr 2d23b84499 New command line option "--terse" for vg_perf.
Fixes BZ#382407.

Produces the following terse output:

-- bigcode1 --
vanilla   :  no: -----  me: -----  ca: -----  he: -----  ca: -----  dr: -----  ma: -----
ra3-005   :  no:  0.0%  me: -4.7%  ca:  0.2%  he: -1.1%  ca: -1.5%  dr: -0.6%  ma:  0.0%
ra3-005-J :  no:  0.0%  me:  0.4%  ca:  0.3%  he: -0.5%  ca: -0.9%  dr:  0.0%  ma:  0.6%
ra3-006   :  no:  0.0%  me:  0.4%  ca:  0.2%  he: -0.0%  ca: -1.2%  dr:  0.0%  ma:  0.0%
ra3-007   :  no:  0.0%  me:  0.7%  ca:  0.5%  he: -0.5%  ca: -0.6%  dr:  0.0%  ma:  1.2%

instead the full output (when the option is not used):
-- bigcode1 --
bigcode1 vanilla:0.09s  no: 1.6s (18.0x, -----)  me: 3.1s (35.0x, -----)  ca:12.7s (140.8x, -----)  he: 2.0s (22.8x, -----)  ca: 3.7s (41.2x, -----)  dr: 2.0s (22.2x, -----)  ma: 1.9s (20.7x, -----)
bigcode1 ra3-005:0.09s  no: 1.6s (17.8x,  1.2%)  me: 3.0s (33.3x,  4.8%)  ca:12.7s (140.7x,  0.1%)  he: 2.0s (22.2x,  2.4%)  ca: 3.6s (40.2x,  2.4%)  dr: 1.9s (21.7x,  2.5%)  ma: 1.9s (20.7x,  0.0%)



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16461
2017-07-22 05:10:05 +00:00
..
2017-05-08 17:21:59 +00:00
2017-05-05 22:13:20 +00:00
2017-05-05 22:13:20 +00:00

=============================================================================
Notes about performance benchmarks
=============================================================================
For each benchmark, here is a brief description and notes about its
strengths and weaknesses.

-----------------------------------------------------------------------------
Artificial stress tests
-----------------------------------------------------------------------------
bigcode1, bigcode2:
- Description: Executes a lot of (nonsensical) code.
- Strengths:   Demonstrates the cost of translation which is a large part
               of runtime, particularly on larger programs.
- Weaknesses:  Highly artificial.

heap:
- Description: Does a lot of heap allocation and deallocation, and has a lot
               of heap blocks live while doing so.
- Strengths:   Stress test for an important sub-system; bug #105039 showed
               that inefficiencies in heap allocation can make a big
               difference to programs that allocate a lot.
- Weaknesses:  Highly artificial -- allocation pattern is not real, and only
               a few different size allocations are used.

sarp:
- Description: Does a lot of stack allocation and deallocation.
- Strengths:   Tests for a specific performance bug that existed in 3.1.0 and
               all earlier versions.
- Weaknesses:  Highly artificial.

-----------------------------------------------------------------------------
Real programs
-----------------------------------------------------------------------------
bz2:
- Description: Burrows-Wheeler compression and decompression.
- Strengths:   A real, widely used program, very similar to the 256.bzip2
               SPEC2000 benchmark.  Not dominated by any code, the hottest
               55 blocks account for only 90% of execution.  Has lots of
               short blocks and stresses the memory system hard.
- Weaknesses:  None, really, it's a good benchmark.

fbench:
- Description: Does some ray-tracing.
- Strengths:   Moderately realistic program.
- Weaknesses:  Dominated by sin and cos, which are not widely used, and are
               hardware-supported on x86 but not on other platforms such as
               PPC.

ffbench: 
- Description: Does a Fast Fourier Transform (FFT).
- Strengths:   Tests common FP ops (mostly adding and multiplying array
               elements), FFT is a very important operation.
- Weaknesses:  Dominated by the inner loop, which is quite long and flatters
               Valgrind due to the small dispatcher overhead.

tinycc:
- Description: A very small and fast C compiler.  A munged version of
               Fabrice Bellard's TinyCC compiling itself multiple times.
- Strengths:   A real program, lots of code (top 100 blocks only account for
               47% of execution), involves large irregular data structures
               (presumably, since it's a compiler).  Does lots of
               malloc/free calls and so changes that make a big improvement
               to perf/heap typically cause a small improvement.
- Weaknesses   None, really, it's a good benchmark.